Corneal biometry apparatus and method

1. A method of validating the identity of a person, said method comprising the steps of: capturing an image of at least part of a cornea of an eye of the person and deriving one or more geometric parameters for each of a plurality of points or areas across said part of the cornea; comparing each of the geometric parameters derived from the person's cornea with a corresponding reference geometric parameter for each of the points or areas of the cornea for that person; and validating the identity of the person based on the comparison of the geometric parameters for said points or areas.

2. A method of validating the identity of a person as claimed in claim 1 , wherein the step of validating the identity of the person involves setting a cumulative maximum value for the difference in each of the geometric parameters on one occasion to another, and only validating the person when the sum of the difference of the parameter comparison for each of said points or areas is less than or equal to said maximum value.

3. A method of validating the identity of a person as claimed in claim 2 , wherein the step of validating the identity of the person involves taking a selection of the geometric parameters for comparison, and only validating the identity of the person when the sum of the parameter comparison for each of said points or areas is less than respective of cumulative maximum values for all of said parameters.

4. A method of validating the identity of a person as claimed in claim 2 , wherein the step of validating the identity of the person involves awarding a predetermined highest score to a least weighted sum difference based on corneal points, areas and/or the total area of imaged cornea, and confirming a matching identity when a comparison of corneal dataset and name or personal identification number with a database of same matches the predetermined highest score with same name or personal identification number.

5. A method of validating the identity of a person as claimed in either of claims 1 or 2 wherein, the step of capturing the image includes an arc step method wherein a vertex of the cornea is located from which a plurality of meridians are developed together with concentric rings, the plurality of points from which each of the geometric parameters is derived being defined by intersections of the meridians and rings.

6. A method of validating the identity of a person as claimed in claim 5 , wherein the image capture involves directing an infrared detector at the eye for alignment of the vertex distance of said detector with the corneal apex and a mechanism for alignment of the optic axis of the device with the visual avis of the eye.

7. A method of validating the identity of a person as claimed in either of claims 1 or 2 , wherein the step of capturing the image involves developing a plurality of cross-sections of the cornea corresponding to the plurality of areas of the cornea, and deriving the geometric parameter from each of the plurality of cornea cross-sections.

8. A method of validating the identity of a person as claimed in claim 7 , wherein the cross-sections are developed by directing a laser at the eye.

9. A method of validating the identity of a person as claimed in any one of claims 1 to 4 also comprising the step of grouping the plurality of points or areas into a plurality of zones together covering the imaged portion of the cornea.

10. A method of validating the identity of a person as claimed in claim 9 , wherein the step of comparing the geometric parameters includes the step of calculating the absolute differences between the geometric parameter derived and the corresponding reference geometric parameter for each of the plurality of points or areas for each of the zones, and summing the absolute differences for each of the zones wherein the summed absolute difference for the specified geometric parameter is compared with the cumulative maximum value for validation of the person.

11. A method of validating the identity of a person as claimed in any one of the preceding claims, wherein the geometric parameter for the cornea includes axial radii, tangential radii, corneal height, corneal elevation, refractive power, axial power, tangential power, corneal thickness, corneal diameter, or a corneal chord.

12. A method of validating the identity of a person as claimed in claim 11 , wherein the geometric parameter is a plurality of the geometric parameters.

13. A method of validating the identity of a person as claimed in either of claim 11 or 10 , wherein the cumulative maximum value for comparison with the summed absolute difference for the geometric parameter of: (i) axial radii is 400 mm; (ii) tangential radii is 2000 mm; and/or (iii) corneal height is 45 microns.

14. A method of validating the identity of a person as claimed in claim 13 , wherein the cumulative maximum value is used when data is captured from a topographical image of the cornea using the arc step method and up to 9,000 points on the cornea.

15. A method of validating the identity of a person as claimed in any one of the preceding claims also comprising the step of weighting or factoring the geometric parameter comparison prior to validation of the identity of the person.

16. A method of validating the identity of a person as claimed in claim 15 , wherein the step of comparing the geometric parameter involves filtering of the geometric parameter for each of the points or areas to retain only those geometric parameters within a preselected range.

17. A method of validating the identity of a person as claimed in claim 16 , wherein the weighting or factoring involves multiplying the summed absolute difference for the specified geometric parameter by the percentage of the plurality of points or areas retained.

18. An apparatus for validating the identity of a person, said apparatus comprising: means for capturing an image of at least part of a cornea of an eye of the person, said imaging means being configured to derive one or more geometric parameters for each of a plurality of points or areas across said part of the cornea; processing means in communication with the imaging means and being configured to compare each of the geometric parameters derived from the person's cornea with a corresponding reference geometric parameter for each of the points or areas of the cornea for that person; and validation means in communication with the processing means and being configured to validate the identity of the person based on the comparison of the geometric parameters for said points or areas.

19. An apparatus for validating the identity of a person as claimed in claim 18 wherein said imaging means includes a video-imaging device servicing a video capture card of a central processing unit.

20. An apparatus for validating the identity of a person as claimed in claim 19 wherein said imaging means is a digital camera able to capture one or multiple digital images servicing the central processing unit which includes a processor.

21. An apparatus for validating the identity of a person as claimed in claim 18 , wherein the imaging means includes an infra-red detector for vertex alignment of said imaging means and visible light being adapted to be directed at the eye and according to an arc step method develop a plurality of meridians together with concentric rings or part thereof.

22. An apparatus for validating the identity of a person as claimed in any one of claims 18 to 21 , wherein the imaging means is a handheld device.

23. An apparatus for validating the identity of a person as claimed in any one of claims 18 to 22 , wherein the imaging means includes a laser being adapted to be directed at the eye to develop a plurality of cross-sections from which the geometric parameter is derived.

24. An apparatus for validating the identity of a person as claimed in any one of claims 18 to 23 , wherein the processing means includes a reference database having the corresponding reference geometric parameter with which each of the geometric parameters is compared for each of the plurality of points or areas across the cornea.

25. An apparatus for validating the identity of a person as claimed in any one of claims 18 to 24 , wherein the validation means includes a validation database having a cumulative maximum value for each of the geometric parameters, the validation means being configured to only validate the person when the sum of the parameter comparison for each of the points or areas is less than said maximum value.

26. An apparatus for validating the identity of a person claimed in any one of the claims 18 to 23 wherein the validation means includes scoring means being configured to award a predetermined highest score to a least weighted sum difference based on corneal points, areas and/or the total area of imaged cornea, the validation means confirming a matching identity when a comparison of corneal dataset and name or personal identification number with a database of same, matches the predetermined highest score with same name or personal identification number.